Improvement in pulp-screens



UNITE-D STATES PATENT OFFICE.

.GEORGE IVEST, OF TYRINGHAM, IWIASSACHUSETTS.

IMPROVEMENT IN PU LP-SCREENS.

Specification forming part of Letters Patent No. 8,306, dated August 19, 1851.

To @ZZ whom it may concern:

Beit known that I, GEORGE WEsr, of Tyringham, in the county of Berkshire and State of Massachusetts, have invented a new and improved pulp-screen for the purpose of cleansing the pulp from knots, dirt, and other improper matter previous to its being manufactured into paper; and I do hereby declare that the following is a fulL-clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings, making a part of this specification, in which- Figure 'l is a top or birds-eye View. Fig. 2 is a vertical section taken at the line X X, Fig. l.

Similar letters of reference indicate corresponding parts in each of the two Iigures.

The nat-ure of my invention consists in applying to a suitable box (the construction ot' which will be hereinafter fully described) a vibrating bottom, which operates similar to a bellows, and which by its downward motion creates a partial vacuum in the box, causing the pulp which is placed upon a screen on the top of the box to be forced between the screenplates by the pressure of the atmosphere. The pulp after passing through the screen falls upon a partition in the box, and the vibrating bottom in its upward motion forces the pulp oft' the partition and through a slot or opening into a receiving-box- To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation.

A A, Fig. l, represents the box, the precise shape of which is seen in Fig. 2.

B represents the partition in the box A, which projects upward at one end to correspond to the shape of the box, and which prevents the pulp from falling upon the bottom or bellows. This partition does not reach the top of the box A A, there being a space between.

O is the vibrating bottom or bellows, attached to the .box A by tacks or nails c c, as seen in Fig. 2. This is constructed of leather and has a foot d on its under side ruiming nearly its extreme length to stiften it.

D is the screen, placed upon the top of the box A A, as seen in Fig. 2. This screen is constructed by placing metal plates e in a frame f, said plates set-ting in grooves or recesses in the frame. A correct idea ot it will be formed by referring to Figs. l and 2. The screens sit upon small steps or cleats g g at each end and may be properly secured to them by screws or otherwise. The steps or cleats g g rest upon the partition B, and they should be of such a height as to allow the screen D to be a short distance below the sides and ends ot' the box A A, thus allowing a recess or box to hold the pulp upon the screen.

E is the receiving-box. This is attached to the side of the box A A, as represented in Figs. l and 2, and into which the pulp is forced through the slot or opening 72.

F is a slide working between guides it, and which covers the slot or opening 7L when desired.

The object in having one end of the box A A projecting upward, as represented in Fig. 2, is to allow the partition B to project upward, and thus prevent the pulp from falling on the vibrating bottom or bellows O.

G is a cover which fits over thehighest portion of the box A A. (See Fig. 2.)

Operation: The pulp being placed upon the screen D, motion may be given to the vibrating bottom or bellows O by means of a crank at. each end, as represented in Fig. 2, or their equivalents. The bellows or vibrating bot tom O upon being drawn down produces a partial vacuum in the box A A, and the pressure of the atmosphere forces the pulp between the plates e e of the screen D, the plates being such a distance apa-rt as to prevent knots, dirt, and other improper matter from passing between them. The pulp then falls upon the partition l5, and is prevented from coming in contact with the vibrating bottom or bellows by means of its upward projection, as described. Upon the bellows being forced upward the pulp is driven through the vslot or opening 7L into the receiving-box E.

XVhen the bellows is in operation, it is necessary to have the receiving-box E nearly full of pulp, so as to cover the opening 7L and prevent air from being drawn through it upon the descent of the bellows. The weight of pulp on the screen D is sufficient to counteract the pressure caused by the upward motion of the bellows, thus allowing no escape of air through the screen. I prefer to have the screen-plates e constructed of brass. The

other parts described may be of wood, with the exception of the bellows; but I doL not oon- Iine myself to anypartieular material.

Having thus described the nature and operation of my invention, what I claim as new, and desire to secure by Letters Patent, is-

The application of the Vibrating bottom or bellows C to the box A A, said boX being oonst-rueted, as described, with the partition B, and the screen D upon its upper surface, by

which arrangement the pulp is forced by atmospheric pressure between the plates of the screen upon the partition B and oft the partition into a receiving-box E, substantially as described.

GEORGE WEST.

'Vitnesses:

S. H. WATKINS, LUMAN CooLEY. 

